Pediatric diseases Flashcards
Genetic causes of pediatric diseases
- Chromosome abberations arising during gametogenesis
- Inherited mutations
Environmental causes of pediatric diseases
- Maternal/placental infections: TORCH, CMV, syphilis, HIV
- Maternal diseases: diabetes, PKU, endocrinopathies
- Drugs and chemicals: i.e. alcohol causes fetal alcohol syndrome; smoking can causes SIDS
Relationship between timing of the prenatal insult and type of anomaly produced
- Early embryonic period (first 3 weeks): can cause death or aborption; if only few cells are affected, recovery without defects is possible
- 3-6 weeks: embryo is very susceptible to teratogenesis
- Fetal period: decreased susceptibility to teratogenesis; more susceptible to growth retardation or injury to already formed organs
Fetal factors causing fetal growth restrictions
- Chromosomal disorders
- Congenital abnormalities or infections
Maternal factors causing fetal growth restrictions
- Vascular diseases: pre-eclampsia, chronic HTN
- Maternal intake of narcotics, alcohol or cigarettes
- Maternal malnutrition
Placental factors causing fetal growth restrictions
- Low implantation of the placenta
- Placental abruption
- Placental infarcation
These factors generally comprise the uteroplacental supply line
Respiratory distress syndrome: pathogenesis
- Associated with: male gender, maternal diabetes, cesarean section delivery
- The immature lung is inable to produce surfactant -> increased tendency for alveolar collapse
- Eventually leads to formation of a hyaline membrane, causing further hypoxemia and CO2 retention
Respiratory distress syndrome: morphology
Early course: necrotic cell debris in terminal bronchioles and alveolar ducts
Later: eosinophilic hyaline membranes line the respiratory bronchioles and other structures
Necrotizing enterocolitis
- Linked to enteral feeding, infectious agents and inflammatory cytokines
- Typically involves the terminal ileum, cecum and right colon, which can appear distended and congested or gangrenous
- Possible consequences include peritonitis and perforations
SIDS: pathogenesis
Triple-risk model:
1. Vulnerable infant (intrinsic stressors): brain stem abnormalities with defect arousal and cardiorespiratory control, low birth weight
- Critical developmental period (0-12 months): young maternal age, smoking, drug abuse etc.
- Exogenous stressors: prone sleep position, sleeping on soft surface, hyperthermia
SIDS: morphology
- Petechia on the thymus, visceral and parietal pleura and epicardium
- Congested lungs
- Pulmonary edema
- Brain stem abnormalities: hypoplasia of the arcuate nucleus
Immune hydrops
- Due to antibody-induced hemolytic disease (blood group (Rh) incompatibility)
- Fetal RBCs cross to the mother during the third trimester -> mother produces antibodies against the fetal RBCs -> antibodies cross the placenta and reach the fetus -> fetal RBC destruction -> anemia -> ischemia
- ABO incompatibility is a milder form and occurs when infants of blood group A or B are born to mothers of blood group O
Non-immune hydrops: etiology
- Chromosomal anomalies resulting in cardiovascular defects; trisomy 21 and 18 and Turner syndrome
- Fetal anemia: i.e. alpha-thalassemia; erythroblastosis fetalis (parvovirus 19 causes RBC death and aplastic anemia)
Non-immune hydrops: morphology
- The fetus and placenta are pale
- Liver and spleen are enlarged
- Compensatory hyperplasia of the BM (due to erythroblastosis fetalis)
Most common benign tumors of infancy and childhood
Hemangioma:
- Benign vascular tumor; cavernous or capillary
- Usually found on the skin
Lymphangioma:
- Lymphatic counterpart of hemangioma
Sacrococcygeal teratoma:
- germ cell tumor
